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LEA-M8S / LEA-M8T - Hardware Integration Manual 

 

UBX-13003140 - R07 

Production Information 

Migration to u-blox M8 modules 

 

 

Page 19 of 31

 

 

3.3

 

Hardware migration LEA-6T -> LEA-M8T 

 
Pin  

LEA-6T 

LEA-M8T 

Remarks for Migration 

Pin Name 

Typical Assignment 

Pin Name 

Typical Assignment 

SDA 

DDC Data 

SDA 

DDC Data 

No difference 

SCL

 

DDC Clock

 

SCL

 

DDC Clock

 

No difference 

TxD

 

Serial Port  

TxD

 

Serial Port 

No difference 

RxD

 

Serial Port

 

RxD

 

Serial Port

 

No difference 

NC

 

Not Connected

 

D_SEL 

D_SEL =1(or open) 

Do not drive low 

VCC

 

Supply voltage

 

VCC

 

Supply voltage

 

No difference 

GND

 

Ground (digital)

 

GND

 

Ground (digital)

 

No difference 

VCC_OUT 

Output voltage 

VCC_OUT 

Output voltage 

No difference 

TIMEPULSE2

 

2

nd

 Timepulse 

Not Connected 

Reserved 

Time Pulse 2 is now 

available on pin 12 
(Safeboot_N / Time Pulse 2) 

10 

RESET_N

 

External Reset

 

RESET_N

 

External Reset

 

No difference 

11 

V_BCKP

 

Backup voltage supply

 

V_BCKP

 

Backup voltage supply

 

If this was connected to GND 
on u-blox 6 module, OK to do 
the same on u-blox M8. 

12 

Safeboot_N

 

Safeboot_N

 

Safeboot_N/ 
TIMEPULSE2

 

Safeboot_N /Timepulse 2

 

Must not be held LO during 
start-up. 

13 

GND 

Ground 

GND 

Ground 

No difference 

14 

GND 

Ground 

GND 

Ground 

No difference 

15 

GND 

Ground 

GND 

Ground 

No difference 

16 

RF_IN

 

GNSS signal input

 

RF_IN

 

GNSS signal input

 

No difference 

17 

GND 

Ground 

GND 

Ground 

No difference 

18 

VCC_RF

 

Output Voltage RF section  VCC_RF

 

Output Voltage RF 
section

 

No difference 

19 

V_ANT 

Antenna Bias voltage 

V_ANT 

Antenna Bias voltage 

No difference

 

20 

AADET_N 

Active Antenna Detect 

EXTINT1/AADET_N 

External Interrupt Pin/ 
Active Antenna Detect 

 

21 

Reserved 

Not Connected 

Reserved 

Not Connected 

No difference 

22 

Reserved 

Not Connected 

Reserved 

Not Connected 

No difference 

23 

Reserved 

Not Connected 

Reserved 

Not Connected 

No difference 

24 

VDD_USB 

USB Supply 

VDD_USB 

USB Supply 

No difference 

25 

USB_DM 

USB Data 

USB_DM 

USB Data 

No difference 

26 

USB_DP 

USB Data 

USB_DP 

USB Data 

No difference 

27 

EXTINT0 

External Interrupt Pin 

EXTINT0 

External Interrupt Pin 

No difference 

28 

TIMEPULSE1 

Timepulse (1PPS) 

TIMEPULSE1 

Timepulse (1PPS) 

No difference 

Table 6: Pin-out comparison LEA-6T vs. LEA-M8T 

3.4

 

Software migration 

 

For  overall description of the module software operation, see the 

u-blox  M8  Receiver Description 

Including Protocol Specification 

[3]. 

 

All features requiring a flash on LEA-6N are not supported on LEA-M8S. (AssistNow offline / save config) 

 

Summary of Contents for LEA-M8S

Page 1: ...al Abstract This document describes the features and specifications of the cost effective and high performance LEA M8S and LEA M8T modules which feature the u blox M8 concurrent GNSS engine with recep...

Page 2: ...LASH version PCN reference LEA M8S LEA M8S 0 00 ROM 2 01 N A LEA M8T LEA M8T 0 01 ROM 2 01 FLASH FW 2 30 TIMRAW 1 02 UBX 15012993 u blox reserves all rights to this document and the information contai...

Page 3: ...ence on I O lines 8 2 Design 9 2 1 Pin description 9 2 2 Minimal design 10 2 3 Footprint and paste mask 10 2 4 Antenna and Antenna supervision 11 2 4 1 Antenna design with passive antenna 11 2 4 2 Act...

Page 4: ...main supply voltage During operation the current drawn by the module can vary by some orders of magnitude especially if enabling low power operation modes For this reason it is important that the sup...

Page 5: ...X3232 Hardware handshake signals and synchronous operation are not supported 1 4 2 USB A USB version 2 0 FS Full Speed 12 Mb s compatible interface is available for communication as an alternative to...

Page 6: ...nformation about the DDC implementation see the u blox M8 Receiver Description Including Protocol Specification 3 For bandwidth information see the LEA M8S Data Sheet 1 For timing parameters consult t...

Page 7: ...he Flash has become corrupted D_SEL Interface select LEA M8T ONLY The D_SEL pin selects the available interfaces SPI cannot be used simultaneously with UART DDC If open UART and DDC are available If p...

Page 8: ...possible to generate noise in the order of volts and not only distort receiver operation but also damage it permanently On the other hand noise generated at the I O pins will emit from unshielded I O...

Page 9: ...pull up resistor to VCC Input pin for optional antenna supervisor circuitry Leave open if not used UART TxD LEA M8S 3 TxD SPI MISO LEA M8T O Serial Port Communication interface can be programmed as TX...

Page 10: ...A M8T passive antenna design For active antenna design see section 2 4 2 3 Footprint and paste mask Figure 5 describes the footprint and provides recommendations for the paste mask for the LEA M8S and...

Page 11: ...ntion to the layout of the RF section Typically a passive antenna is located near electronic components therefore care should be taken to reduce electrical noise that may interfere with the antenna pe...

Page 12: ...Active antenna design Active antennas have an integrated low noise amplifier Active antennas require a power supply that will contribute to the total GNSS system power consumption budget with addition...

Page 13: ...8T Data Sheet 2 For recommended parts see Appendix In case VCC_RF voltage does not match with the antenna supply voltage use a filtered external supply as shown in Figure 10 Antenna design with active...

Page 14: ...cuit see Figure 14 High on AADET_N means that an external antenna is not connected Status reporting At startup and on every change of the antenna supervisor configuration the LEA M8S and LEA M8T modul...

Page 15: ...ceiver Description Including Protocol Specification 3 Short circuits on the antenna input without limitation R_BIAS of the current can result in permanent damage to the receiver Therefore it is mandat...

Page 16: ...band at 1 561 GHz Therefore it is not recommended to use digital supply nets to feed the V_ANT pin Figure 13 Module design with active antenna external supply for exact pin orientation see the LEA M8S...

Page 17: ...formation Design Page 17 of 31 RF Vcc Rbias R R R I _ 3 2 2 Equation 1 Calculation of threshold current for open circuit detection If the antenna supply voltage is not derived from VCC_RF do not excee...

Page 18: ...upply voltage No difference 7 GND Ground digital GND Ground digital No difference 8 VCC_OUT Output voltage VCC_OUT Output voltage No difference 9 NC Not Connected Reserved Not Connected No difference...

Page 19: ...LO during start up 13 GND Ground GND Ground No difference 14 GND Ground GND Ground No difference 15 GND Ground GND Ground No difference 16 RF_IN GNSS signal input RF_IN GNSS signal input No differenc...

Page 20: ...the solder joints on the connectors half vias should meet the appropriate IPC specification Reflow soldering A convection type soldering oven is highly recommended over the infrared type radiation ove...

Page 21: ...oldering the u blox M8 module consider an optical inspection step to check whether The module is properly aligned and centered over the pads All pads are properly soldered No excess solder has created...

Page 22: ...ixture soldering e g pins 1 and 15 and then continue from left to right Rework The u blox M8 module can be unsoldered from the baseboard using a hot air gun When using a hot air gun for unsoldering th...

Page 23: ...EMI handling and protection measures To prevent overstress damage at the RF_IN of your receiver never exceed the maximum input power see the LEA M8S Data Sheet 1 and the NEO LEA M8T Data Sheet 2 Elec...

Page 24: ...asures Using an LNA with appropriate ESD rating can provide enhanced GNSS performance with passive antennas and increases ESD protection Most defects caused by ESD can be prevented by following strict...

Page 25: ...ce EMI Electromagnetic interference EMI is the addition or coupling of energy causing a spontaneous reset of the GNSS receiver or resulting in unstable performance In addition to EMI degradation due t...

Page 26: ...filter is needed on the GNSS side to block the high energy emitted by the GSM transmitter Examples of these kinds of filters would be the SAW Filters from Epcos B9444 or B7839 or Murata Increasing int...

Page 27: ...from the GNSS carrier see Figure 20 The main sources are wireless communication systems such as GSM CDMA WCDMA Wi Fi BT etc 0 500 1000 1500 2000 GPS input filter characteristics 0 110 0 500 1500 2000...

Page 28: ...ou Low insertion loss LNA JRC NJG1143UA2 LNA Low noise figure up to 15 dBm RF input power Avago ALM GN001 LNA Low noise figure with pre LNA filter concurrent GNSS Avago ALM GN002 LNA Very low noise fi...

Page 29: ...ant Antenna SAW LNA On chip LNA SAW Passive GNSS Antenna Active GNSS Antenna SAW 2G cellular 3G 4G cellular 2G 3G 4G cellular MAX 6 Any NEO 6 Any LEA 6 Any EVA 7 M MAX 7 C W Q NEO 7 N M P EVA M8 M MAX...

Page 30: ...S 09007 For regular updates to u blox documentation and to receive product change notifications please register on our homepage http www u blox com Revision history Revision Date Name Status Comments...

Page 31: ...Phone 65 6734 3811 E mail info_ap u blox com Support support_ap u blox com Regional Office Australia Phone 61 2 8448 2016 E mail info_anz u blox com Support support_ap u blox com Regional Office Chin...

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